(Reuters) — Valeant Pharmaceuticals International Inc. said a group of company executives will take over until CEO Michael Pearson returns from medical leave.

.Pearson, who joined Valeant as CEO in 2010 after a 23-year career at McKinsey & Co., will be on a medical leave of absence, effective immediately, the company said in a statement on Monday.

The Canadian drugmaker's U.S.-listed shares fell about 7 percent in premarket trading.

Pearson was hospitalized with a "severe case of pneumonia" on Friday and is receiving treatment, a company spokeswoman said last week.

Valeant's board has created an "office of the Chief Executive Officer," which will include general counsel Robert Chai-Onn, company group chairman Ari Kellen and chief financial officer Robert Rosiello.

The board has also created a committee to oversee and support the office of the CEO, and it will include lead independent director Robert Ingram, president of ValueAct Capital Mason Morfit and former Valeant CFO Howard Schiller.

Pearson's illness comes as investors are turning up pressure on the Laval, Quebec-based company to provide a more detailed plan on how it will grow profits in 2016. Under Pearson, the company has come under U.S. government scrutiny for acquiring off-patent drugs and dramatically hiking prices.

Under a deal announced this month, Walgreens Boots Alliance will take over many of the functions that had previously been managed by Philidor Rx Services, the specialty pharmacy with which Valeant cut ties in response to allegations of aggressive billing practices.